1. Field of the Invention
The present invention relates generally to the field of medical imaging, and, more particularly, to a semi-local active contour for a faint region detection in knee computed tomography (“CT”) images.
2. Description of the Related Art
Detection of specific anatomic structures in medical images is an important research problem in Computer Aided Diagnosis (“CAD”) applications. Consider, for example, the segmentation problem shown in FIG. 1. Two regions of interest, which refer to infrapatellar fat of the knee joint (also known as Hoffa's pad), are labeled roughly by ellipses. The two images shown in FIG. 1 are two slices from a knee computed tomography (“CT”) sequence. Slices 25 and 33 are shown from an axial knee CT sequence of 53 slices. Referring to FIG. 2, the two regions of interest of FIG. 1 are refined by a clinician by hand to show the actual boundaries of the Hoffa's pad, according to that clinician. FIG. 2 may be used, for example, to validate automated methods of segmenting and/or analyzing anatomical structures in medical images.
It is generally desirable for a clinician to understand the physiomechanical properties of the knee fat during flexion and extension of the knee. By outlining the target area, the clinician can obtain the shape or surface of the knee fat, and the bending/extending characteristics of the knee fat can be analyzed. The clinician can also facilitate a quantitative measurement for the amount of shape change in extended knee fat and flexed knee fat. The understanding of knee function and pathology may be increased by the study of shape and deformation from the extracted Hoffa's pad in flexed and extended knee medical images.